DE69910718T2 - Color cathode ray tube - Google Patents

Description

The present invention relates to a color cathode ray tube, which, for example, in a television set or a computer display is used. It relates in particular to a color selection electrode structure with a one-dimensional tension mask, in which a color selection electrode is stretched in the minor axis or major axis direction.

A color cathode ray tube has generally has a color selection electrode structure that has a color selection electrode, around three electron beams emitted by an electron gun to choose according to their color and includes a frame for holding this color selection electrode.

There are several types of color selection electrodes, such as press masks, which are manufactured by pressing a flat plate member provided with, for example, slotted, round or elliptical openings into a predetermined curved shape and welding it to a frame (see 4 (a) ), two-dimensional tension masks, in which a similar plate member with several openings is stretched in the minor and major axis directions while exerting tension and welded to a frame (see 4 (b) ), one-dimensional tension masks, in which a similar plate member with several openings is stretched by applying tension in either the minor or major axis direction and welded to a frame (see 4 (c) ) and opening grilles, in which a link with several metallic slim elements is stretched while being subjected to tensile stress and welded to a frame (see publication of Japanese Unexamined Patent Application (Tokkai) No. Hei 4-163830 = or US-A-5,214,349).

Sheets of color cathode ray tubes are made in the youngest Time designed to be flatter, as this causes the reflection of external light reduced and their appearance is improved. A flatter plate requires that too the color selection electrode becomes flatter to between the fluorescent screen and maintain the correct distance between the color selection electrode.

However, making a press mask flatter does the trick a larger "bulge", which means that the thermal expansion the color selection electrode because of the absorption of electron beams increases, causing a shift in the openings in the color selection electrode caused. As a result, electron beams passing through this opening do not strike properly on the predetermined phosphors, resulting in color irregularities to lead can. Because the curved area formed by pressing, it is also likely that their flattening permanent deformation (sinking due to a shock during Dropping caused. To make the color choice electrode flat is therefore very difficult.

With the two-dimensional tension mask it is due to the fact that in the minor and major axes tension is applied to the color selection electrode, difficult between the tension in these directions has a corresponding symmetry maintain so that the color selection electrode does not warp.

It also causes the opening grille with several stretched slim metallic elements to that effect Problems that an external shock can easily cause vibrations of the color selection electrode and such Vibrations be great can and are difficult to stop. In addition, the handling of the Color choice electrode difficult to assemble because of the slim metallic Entangling and breaking elements in general.

Compared to these types of color choice electrodes points the one-dimensional tension mask with regard to this Problems on an advantageous structure. It is therefore increasing for the Color choice electrode in color cathode ray tubes with a flat plate used.

With the one-dimensional tension mask however, that is outside of the perforated area lying not perforated Area in a major axis direction stronger than the perforated area, when the color selection electrode is stretched on a frame that goes along the main axis is curved is while tensile stress is exerted in the minor axis direction. The stress is therefore concentrated in the non-perforated Area, and it is difficult to perforate in the peripheral part of the Area in the major axis direction (near the non-perforated Area) to exert a tension. As a result, the color selection electrode is likely to be due to insufficient tension swings in this peripheral part.

The one-dimensional tension mask points on the other hand, between adjacent openings in the perforated Field of color selection electrode (referred to as "bridge parts") parts without openings on. Even if the color selection electrode is only in the minor axis direction applied tension is stretched, there is a slight force in the main axis direction exercised. If this force in the main axis direction is too small, then the color selection electrode warps in general. In particular a heat treatment at Manufacturing process of Color cathode ray tube can make such faults obvious and misalignment of the openings.

To solve these problems, an object of the present invention is to provide a color cathode ray tube having an excellent color purity, which has a color selection electrode structure in which vibrations cannot easily occur, and the color selection electrode de not warped because sufficient tensile stress is exerted in the peripheral part of a perforated area of the color selection electrode.

To solve the above-mentioned problems includes a Color cathode ray tube according to the present Invention: one made from a plate with an inner surface which is formed a phosphor screen, and a funnel Piston; a color selection electrode that is inside the bulb of the fluorescent screen across from is trained; and a frame for fixing and holding the color selection electrode. The color choice electrode is either by exercising tension stretched in a minor axis direction or a major axis direction. The color selection electrode contains: a holed Area provided with a plurality of openings arranged with a predetermined center distance and is not a holed one Area related to a direction that is substantially perpendicular to the direction in which the color selection electrode is stretched outside of the perforated Area is arranged. The non-perforated area is expanding gradually from a central part in the direction in which the color selection electrode is stretched to final parts.

With such a color cathode ray tube the tensile stress in the peripheral part of the color selection electrode in the direction, which is substantially perpendicular to the direction in which the color selection electrode is stretched, substantially equal to that be made in the middle part. It is also possible to have a force in this Direction in the circumferential part regarding maintain that direction. Vibrations in the peripheral part the color selection electrode suppressed accordingly become. Moreover distortion of the color selection electrode can be suppressed so that it is too no misalignment of openings comes. Thus, a high quality color cathode ray tube can be used excellent color purity can be provided.

It is preferred that 1.2 ≦ b / a ≦ 6.0 is sufficient where "a" is a width of the middle part of the not perforated Area and "b" a latitude of End parts is.

If this relationship is fulfilled, the tensile stress in the peripheral part of the perforated area of the color selection electrode in terms of a direction that is substantially perpendicular to the direction in which the color selection electrode is stretched within a desired one Range are kept.

It is preferred that an edge the color selection electrode in the middle part of the not perforated Area and edges of the end parts of the non-perforated area by a smooth curve or straight line are connected.

With this configuration you can a continuous stress distribution in the end parts in both sides regarding the direction which is substantially perpendicular to the direction in which the color selection electrode is stretched.

It is preferred that in the not holed Area semi-etched holes are provided. Throughout this specification, "half-etched holes" refer to holes that are only partially etched through the thickness of the panel.

With such a configuration can stress concentrations in the not holed Area are reduced, which increases the tensile stress, on the peripheral part of the color selection electrode in one direction is exercised which is substantially perpendicular to the direction in which the color selection electrode is stretched.

It is preferred that the direction in which the color selection electrode is stretched, the minor axis direction is.

1 Fig. 12 is a perspective view showing a color selection electrode structure of a color cathode ray tube according to the first embodiment according to the present invention.

2 Fig. 10 is a sectional side view showing a color cathode ray tube according to the first embodiment of the present invention.

3 Fig. 12 is a graph showing the relationship of local tension to tension in a central part of the perforated area on a color selection electrode of the present invention as a function of distance from the central part in the major axis direction.

The 4 (a) to (C) are perspective views showing several types of color selection electrode structures.

A detailed follows Description of the present invention with reference to the accompanying Drawings.

First embodiment

2 shows a sectional side view of a color cathode ray tube according to the first embodiment. 1 FIG. 12 shows a perspective view of a color selection electrode structure of a color cathode ray tube of the present invention.

As in 2 is shown, a color cathode ray tube according to the present invention includes a plunger with a plate 2 with a fluorescent screen on the inside 1 is formed, and one with the back of the plate 2 connected funnel 3 , In a neck part 3a of the funnel 3 is an electron gun 5 provided an electron beam 4 emitted. A diversion yoke 6 to deflect the electron beam 4 is on a peripheral surface of the funnel 3 intended. Fluorescent dots of three colors are on the inside surface of the plate 2 applied, causing the fluorescent screen 1 is formed. A plate-shaped color selection electrode 7 is essentially parallel to the fluorescent screen 1 arranged. The color choice electrode 7 has multiple openings formed by etching a flat plate formed and aligned in an order, and selects that from the electron gun 5 emitted three electron beams 4 according to their color. The color choice electrode 7 is through a frame 8th kept, creating a color choice electrode structure 9 is formed. The color choice electrode structure 9 is supported within the piston by one in the frame 8th installed elastic support 10 in one in the plate 2 embedded plate pin 11 intervenes.

As in 1 is shown, the color selection electrode structure 9 by stretching and welding the color selection electrode 7 to the frame 8th with tension in the minor axis direction (ie arrow directions 15 ) educated.

The frame 8th contains a pair of long side links 8a with a substantially triangular cross section and a pair of short side links 8b with a substantially U-shaped cross section. The front surface of the long side links 8a (ie the surface to which the color selection electrode 7 is welded) is a curved surface (cylindrical surface) projecting to the phosphor screen with a predetermined radius of curvature. That is why the color choice electrode 7 on the frame 8th fixed while being curved along its major axis.

The color choice electrode 7 contains a perforated area 13 with several essentially elliptical openings 12 and two unperforated areas 14 outside the perforated area 13 in the major axis direction. The width "b" of the non-perforated areas 14 with respect to the major axis direction at the two end parts in the minor axis direction is larger than the width "a" of a central part.

The following is an explanation of a method of manufacturing a color selection electrode structure 9 a color cathode ray tube according to the present embodiment. First the side faces of the long side links 8a of the frame 8th on 3 to 9 Compression points are compressed while a load with a predetermined distribution is applied within the elastic region. Then, while maintaining this pressure, a color selection electrode 7 in the minor axis direction (ie arrow directions 15 ) stretched with a total tensile stress of about 200 kilopond, and by welding on the curved surfaces of the long side members 8a fixed. When the load is finally removed that is on the long side links 8a has been exercised, acts on the color selection electrode 7 a tension with the desired distribution. In this way, the color selection electrode structure 9 generated.

In the present embodiment For example, a color selection electrode structure was generated in a color cathode ray tube for a 68th cm (29 inch) TV was used.

The color selection electrode has one Plate thickness of 0.1 mm and is for example made of Fe, 42% Ni-Fe or 36% Ni-Fe. The color selection electrode has several arranged with a predetermined center distance and a predetermined distribution, essentially elliptical openings. The color selection electrode has a substantially rectangular perforated Area from (vertical by horizontal) 384 mm × 509 mm. The width in the major axis direction of the outside of the holed Area in the main axis direction not perforated Areas 5 mm in a middle part and 11.3 mm in both end parts with respect to the Minor axis direction. Moreover are edges of these parts of the non-perforated areas by a smooth curve with a radius of curvature of R = 3338 mm connected.

The frame contains a pair of long side links, which consists of 36% Ni-Fe with a plate thickness of 1.4 mm and an im substantial triangular cross-section are made, and a pair Short side links made of 42% Ni-Fe also with a plate thickness made of 1.4 mm with a substantially U-shaped cross section are. Its size is (vertical times horizontal) 414 mm × 534 mm.

3 Fig. 12 shows the result of an experiment which illustrates the effect of the present embodiment. The graphical representation in 3 illustrates the relationship of local tension to tension in a central portion of the perforated area on the stretched and welded color selection electrode as a function of distance from the central portion with respect to the major axis direction. The four curves 16 to 19 denote different width ratios of the middle part to the two end parts of the non-perforated areas with respect to the minor axis direction. If the width in the central part of the non-perforated areas is indicated by "a" and the width in the two end parts of the non-perforated areas in the minor axis direction is indicated by "b", then curve is illustrated 16 b / a = 2.26 (in the present embodiment a = 5 mm, b = 11.3 mm), curve 17 b / a = 1.0, curve 18 b / a = 1.2 and curve 19 b / a = 6.0.

Curve 16 Fig. 12 shows the present embodiment in which the amounts of tension in the peripheral parts in the major axis direction and in the central part of the perforated area are substantially the same. This is possible because by widening the non-perforated areas in the two end parts in the minor axis direction compared to the central part when stretching in the direction of the diagonal axis (arrow direction 20 in 1 ) the color selection electrode is subjected to a stress by which the stress on the non-perforated areas is reduced in the direction in which the color selection electrode is stretched, so that the circumferential part in the major axis direction in the perforated area (ie in a part of the perforated area tensile stress exerted in the vicinity of the non-perforated area) can be edited.

Curve 17 shows the case where the width of the non-perforated areas is the same in both end parts in the minor axis direction and the central part. In this case, the tensile stress acting in the circumferential part of the perforated area in the main axis direction is smaller than that in the central part because the concentration of the stress on the non-perforated areas in the direction in which the color selection electrode is stretched is that in the circumferential part in the main axis direction perforated area (ie, part of the perforated area near the non-perforated areas) reduced tensile stress.

/mm² , was in 3 durch Kurve 16 angegeben ist. In diesem Fall betrug die Breite des mittleren Teils a = 5 mm und die Breite der Endteile b = 11,3 mm.In the above experiment, the force per unit area in the major axis direction in the present embodiment measured in the peripheral part of the perforated area in the major axis direction was 0.024 k

/ mm ² what in 3 through curve 16 is specified. In this case, the width of the middle part was a = 5 mm and the width of the end parts was b = 11.3 mm.

/m².In the case of the curve 17 where the width of the non-perforated areas in the major axis direction was made 5 mm at both end parts with respect to the minor axis direction and in the central part, the force per unit area in the major axis direction was 0.008 k

/ m ² .

As a result, it has been found that through Using a width ratio b / a = 2.26 for who did not perforate Areas of the color selection electrode and a resulting broadening who did not holed Areas in both end parts are insufficient compared to the middle part Tension in the peripheral part of the perforated area in the major axis direction can be avoided better than if the aspect ratio b / a = 1.0 (this means, the width of the end parts is equal to the width of the middle part), and a force about three times greater can be exercised in the major axis direction.

These effects, when insufficient tensile stress in the circumferential part of the perforated area in the main axis direction is avoided and a force is exerted in the main axis direction, arise already at 1.0 <b / a, but in practice it is preferred that 1.2 ≦ b / a, that is, the aspect ratio is larger than in the case of the curve 18 ,

In the case of the curve 19 (where the non-perforated areas in both end parts in the minor axis direction are 6.0 times wider than the central part), on the other hand, the tensile stress in the peripheral part in the major axis direction becomes about 10% higher than the tensile stress in the central part, as in FIG 3 you can see. In this way, as the ratio b / a of the width of the end parts in the minor axis direction to the width of the central part of the non-perforated areas becomes larger, the tensile stress in the peripheral part in the main axis direction in the perforated area also increases. However, if the tensile stress in the circumferential part in the main axis direction is too large, the circumferential part of the color selection electrode is stretched more than the central part, so that when the color selection electrode vibrates due to a shock, the circumferential part becomes a vibration node that hardly vibrates and starts instead the middle part vibrates too much, which makes it difficult to dampen the vibration. It is therefore preferred that the ratio of the width "b" of the end parts in the minor axis direction to the width "a" of the middle part is not too large. Taking curve into account 19 (where b / a = 6.0) as a suitable upper limit for b / a, the preferred range is 1.2 ≦ b / a ≦ 6.0.

Thus, in the direction of one diagonal axis of the color selection electrode during stretching according to the present embodiment exerted a strain, by the end portions of the non-perforated areas with respect to the Minor axis direction, the outside of the holed Area in the major axis direction, in the major axis direction be made wider than the middle part. This allows a insufficient tensile stress in the peripheral part of the perforated Avoid area in the major axis direction.

The color selection electrode also warps not because a greater force is exerted in the main axis direction can.

By the color cathode ray tube according to the present Invention can thus achieve excellent color purity be sufficient, as on the peripheral part of the perforated area Tension exerted is so that the color selection electrode across from Resistant to vibrations and is not distorted.

Second embodiment

A description of the second follows Embodiment.

In this embodiment, in the perforated Provided semi-etched holes in areas of the color selection electrode (e.g., not through holes with a depth of 30% of the plate thickness, its shape and center distance those of the openings in the holed Area essentially the same). All other aspects are that same as in the first embodiment.

In this way it can be based on the not holed Area exercised Stress can be reduced, causing the tensile stress on the peripheral part of the holed Area of the color selection electrode is enlarged in the major axis direction.

Accordingly, by avoiding insufficient tensile stress in the peripheral part of the perforated area in the main axis direction, it is possible to provide a color selection electrode which is resistant to vibrations dig, and to realize a color cathode ray tube with excellent color purity.

In the first and second embodiments of the present Invention as described above are the edges of the middle Part of the not perforated Areas and the two end parts in the minor axis direction connected a smooth curve, but the present invention not necessarily limited to this structure. Instead, they can Edges of the central part of the non-perforated areas and the two End parts in the minor axis direction also connected by straight lines be, the distribution of the stress in the end parts in the main axis direction of the color selection electrode smoothed and while stretching prevents breakage.

In the above embodiments is also the front surface of the long side members of the frame are curved, and the color selection electrode structure is constructed by welding the color selection electrode to this curved surface, but the present invention is not limited to this configuration. The The present invention can also have an effect, for example be obtained when the color selection electrode is attached to a flat frame welded is going to instead of a curved one front surface a substantially flat surface to create.

They also described the above embodiments a color selection electrode with tensile stress exerted in the minor axis direction, however, the effect of the present invention is not on this configuration limited. The same effect can be obtained if the color selection electrode is on the short side members of a frame are welded, being in the major axis direction exerted a tension becomes. In this case, the multiple openings are for the passage of Electron beams formed so that their longitudinal axis with the major axis direction the color selection electrode coincides. Moreover are not perforated areas the color selection electrode outside of the holed Area in the minor axis direction, and the end portions of the non-perforated Areas are the end parts in the major axis direction.

Claims (6)

A color cathode ray tube comprising: a bulb comprising: a plate having an inner surface on which a phosphor screen is formed and a funnel; a color selection electrode formed inside the bulb opposite the phosphor screen; a frame for fixing and holding the color selection electrode; characterized in that the color selection electrode is stretched in either a minor axis direction or a major axis direction by the application of tensile stress; the color selection electrode comprising: a perforated area provided with a plurality of openings arranged at a predetermined pitch and an unpunched area outside of a direction substantially perpendicular to the direction in which the color selection electrode is stretched of the perforated area, and the non-perforated area gradually widens from a central part of the non-perforated area in the direction in which the color selection electrode is stretched toward end portions of the non-perforated area. A color cathode ray tube according to claim 1, which satisfies 1.2 <b / a ≦ 6.0, where "a" is a width of the middle part of the not holed Area and "b" a latitude of End parts of the not perforated Area is. Color cathode ray tube according to claim 1 or 2, characterized in that a Edge of the color selection electrode in the middle part of the not perforated Area and edges of the end parts of the non-perforated area by a smooth curve are connected. Color cathode ray tube according to claim 1 or 2, characterized in that a Edge of the color selection electrode in the middle part of the non-perforated Area and edges of the end parts of the non-perforated area by a straight line are connected. Color cathode ray tube according to one of claims 1 to 4, characterized in that in the not holed Area semi-etched holes are provided. Color cathode ray tube according to one of claims 1 to 5, characterized in that the direction in which the color selection electrode is stretched, the minor axis direction is.